The CARMENES search for exoplanets around M dwarfs - HD 147379b: A nearby Neptune in the temperate zone of an early-M dwarf

Abstract

We report on the first star discovered to host a planet detected by radial velocity (RV) observations obtained within the CARMENES survey for exoplanets around M dwarfs. HD 147379 ($V=8.9$ mag, $M=0.58\pm 0.08$ M${}_{\odot }$), a bright M0.0V star at a distance of 10.7 pc, is found to undergo periodic RV variations with a semi-amplitude of $K=5.1\pm 0.4$ m s${}^{-1}$ and a period of $P=86.54\pm 0.06$ d. The RV signal is found in our CARMENES data, which were taken between 2016 and 2017, and is supported by HIRES/Keck observations that were obtained since 2000. The RV variations are interpreted as resulting from a planet of minimum mass $m_{\mathrm{p}}\sin i=25\pm 2$ M${}_{\oplus }$, 1.5 times the mass of Neptune, with an orbital semi-major axis $a=0.32$ au and low eccentricity ($e<0.13$). HD 147379b is orbiting inside the temperate zone around the star, where water could exist in liquid form. The RV time-series and various spectroscopic indicators show additional hints of variations at an approximate period of 21.1d (and its first harmonic), which we attribute to the rotation period of the star.

accepted for publication as A&A Letter

References in corpus (14)

• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• A terrestrial planet candidate in a temperate orbit around Proxima Centauri
• Habitable Zones Around Main-Sequence Stars: Dependence on Planetary Mass
• The Solar Neighborhood XVII: Parallax Results from the CTIOPI 0.9m Program -- Twenty New Members of the RECONS 10 Parsec Sample
• Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
• The H$\alpha$ emission of nearby M dwarfs and its relation to stellar rotation
• A Re-appraisal of the Habitability of Planets Around M Dwarf Stars
• Generalized investigation of the rotation-activity relation: Favouring rotation period instead of Rossby number
• CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS
• Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics
• New Distant Companions to Known Nearby Stars. II. Faint companions of Hipparcos stars and the frequency of wide binary systems
• Accounting for velocity jitter in planet search surveys
• The HARPS search for southern extra-solar planets XXXV. Planetary systems and stellar activity of the M dwarfs GJ 3293, GJ 3341, and GJ 3543

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• The California Legacy Survey I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades
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